Projectile



April 30, -1 c. ARAGONE i#399,747

' PROJECTILE Filfi Sept. 26, 1954 3 Sheets-Sheet 3 Patented pr. 30, 1935 ERQJECE Carlo Aragone, La Spezia, Etaly Application September 26, 1934, Serial No. 745,633 In Switzerland October 1'7, 1933 6 Claims.

The subject of the present invention is a fuse for an artillery projectile. comprising a timing .mechahism adapted to control a percussion mechanism in such manner that the latter determines, as a function of the time, the bursting of the projectile.

The fuse is characterized in this that it comprises at least one body, the initial position of which is regulatable and which under the influence of centrifugal force produced by the rotation of the projectile is displaced on a helicoidal path of progressive radius, entrains in its movement the first timing wheel of thetiming mechanism and, at the end of its travel, actuates the percussion member causing defiagration of a percussion cap.

In the fuse of the present invention, the oscillations of the balance wheel regulating the timing mechanism are thus maintained by one or more masses subjected to centrifugal force which the rotation of the projectile produces, but, in lieu of being connected by gearing to the clockwork movement and of effecting a translatory radial and rectilinear movement relatively to their support, as in certain known constructions, the mass or masses traverses or traverse a helicoidal path of progressive radius, for example, on a race or track formed as a groove on the surface of a recess in the support. This race or track is preferably developed on the surface of a recess in the support of approximately conical or parabolic form.

The annexed drawings illustrate by way of ex ample one embodiment of the invention.

Fig. 1 shows in longitudinal section the head of the projectile.

Fig. 2 is a section on the line II-II of Fig. 1.

Fig. 3 is a part section, to enlarged scale, on the line IIIIII of Fig 1.

Fig. 4 is a section on the line IV-IV of Fig. 1.

Fig.5 is a section on the line V-V of Fig. 1.

Figffi is a diagrammatic view, in elevation, of the timing mechanism.

Fig. 7 is a section to enlarged scale on the line,

VII--VII of Fig. 1.

In the drawings is shown the head of an artillery projectile comprising a double acting fuse. The head includes a base 9 intended to be screwed on the base of the projectile, a "seating 8 and a cap or ogive 9 which is screwed on the seating 8. The seating 8 forms the support for the timing mechanism and comprises a bridge ID in which is screwed a tubular sheath II the front end of which is fitted in a cylindrical recess l2 in the ogive 9. The sheath H is located axially of the projectile and encloses a torsion spring i3 formed by a steel wire of circular section; This spring is fixed at its front end in a bearing it and is connected at its rear end by means of a joint I5 to the axis of the balance wheel 96, the front pivot of which is connected to'the joint IS. The rear pivot of the balance wheel l6 rotates in a bearing H in the seating 8'. The spring I3 is protected within the tubular sheath II and may oscillate therein freely about its axis to impart an oscillating movement to the balance wheel I6. The joint I5 permits the spring Hi to expand axially without adversely affecting the operation of the balance wheel.

The timing mechanism comprises, in addition to the spring 13 and the balance wheel IS, a lever-escapement comprising a side lever I8 (Fig. 3), the fork of which actuates the pin on the plate fixed on the axis of the balance wheel, an escapement wheel 19, the pinion of which engages with a counting wheel 20 in one with the pinion .pf the counter 2|, and a timing wheel formed by an internally toothed crown 22 meshing with the pinion of the counter 21. The balance wheel, the parts of the escapement and the movable member 29, 2|, are disposed in recesses or cavities in the seating 8', while the toothed crown 22 is fitted in the first timing wheel 23 forming the driving wheel. This driving wheel is mounted loosely on a spindle 24 having four blades disposed in cruciform and each of which is formed on its periphery with a groove or channel 25 inclined towards the axis of rotation 24 of the wheel along the generatrix of an inverted cone.

The axis of rotation 24 is mounted at its front end in the seating 8 by means of a spring shock absorbing fitting 26 and, at the other end,

. in the base 8 to which it is fixed by a nut 21.

This iimer end of the spindle '24 terminates in a striker 28, intended to cooperate with a cap or cup 29 carrying a pellet of fulminate 39 inorder to ignite the charge by percussion, when the projectile strikes an obstacle. The cap 29 is held in place by two balls 3| interposed between the nut 21 and the cup. These balls are located in a compartment communicating with a passage 32, the opening of which is closed by a safety spring 33 intended to surround, by inertia, on discharge, the cap 29. Due to this fact, the open-' ing of the passage 32 is uncovered so that the balls 3| may leave their seating by the passage 32, under the action of centrifugal force as soon as the projectile receives a tangential acceleration. Then, the cap 29 will be able to move forward by inertia so that the pellet 36 strikes the point 28 to produce ignition of the charge, the pellet 30 communicating with the detonating chamber 34 which communicates in turn by an orifice 34' provided in a diaphragm 35 with a flame passage connected to the explosion chamber of the charge.

The cap 29 may be locked externally of the projectile by means of a locking rod 36 comprising a screw-threaded head 36' which can be turned by means of a screw driver to advance or retract the rod 36.

The driving wheel 23 is encased and can intate freely by its blades in a paraboloidal recess 31 in the base 8. On the paraboloidal wall of the recess 37 is a grooved helicoidal race or track 38 of progressive radius developing from the inner end to the outer end of the recess on a regular pitch. On this helicoidal race or track are disposed four balls 39 offset by 90 from one another and each of which is freely engaged in one of the channels 25 of the driving wheel 23. The outer end of the helicoidal race or track 38 communicates by a. lateral opening 4|] with a recess 4| inclined to the plane ofrotation of the projectile and allowing passage to one of the balls 39. In the bottom of the recess 4| is disposed a striker 42 intended to strike a. fulminate percussion pellet 43 communicating with the detonating chamber 34 by a flame passage 44. The striker 42 (Figs. 1 and 7) is normally held bya cylindrical locking member '45 connected by means of a rod 46 to a head 41. This locking member isheld in the bottom of its recess by a recoil spring 48 located between the head 41 and a plug 49. In this position of the striker 42, the head 41 of the locking member engages in a notch in the striker in such manner that the latter is held locked; but as soon as the locking member 45 is projected forwards due to inertia, against the spring 48 and under the action of tangential acceleration of the projectile, the head 41 disengages the notch in the stricker releasing the latter. I

The driving wheel 23 is held to the seating 8' normally i. e. before discharge of the shot, by means of two locking pins 56, 5| or the like constituting two movable bolts, one 50 of which is disposed parallel to the axis of rotation of the projectile, while the other 5| is disposed radially. The locking pin 56 is held engaged in an opening in the seating'8' by a deformable metal wire 52 in such manner that the locking pin may be released from the seating 8' and moved rearwards, by inertia, breaking the wire 52, under the action of the axial acceleration of the, projectile on explosion of the charge. The locking pin 5|, in turn, is moved outwards by inertia and is lodged in a recess 5| under the action of centrifugal force as soon as the projectile is given a tangential acceleration. Displacement of the locking pins or the like 50, 5| ensures that the driving wheel 23 is released from the seating 8'. The latter, with the ogive 9, may turn on the base 8 which is provided for this purpose with a circular guide groove 53 in which a pin 54 fixed to the seating 8' is engaged and may turn. This pin moves in the groove 53 when the seating 8' is rotated with the ogive 9 in relation to the base 8 of the head; it may be combined with an indicator for the number of rotations (not shown in the drawings) and cooperate with the latter in such manner that the number of turns eifected by the seating 8', from its original position, indicated by a reference arrow 66 marked on the base 8 of the head, may

be indicated by the indicator. The latter, the construction of which is usual, will be arranged in the base 8 and its indicating member will be visible through an opening formed in the base 8. It may have a stop member against which the pin 54 will abut after a definite number of turns of the seating 8', in order to limit the direct rotary movement of, the latter.

The inner edge of the groove 53 forms a sharp corner on which abut three recesses 55, located in the seating 8'. In each of these recesses is fitted, by its rod, a locking pin 56, the truncated head of which permits the ogive 9 to be screwed on the seating 8. The stem of the pin 56 is bevelled at its end and carries a. flange 58 of soft metal disposed in a lateral notch 59 in the seating 8'. This flange of U-form engages with its limbs in two corresponding notches of the stem of the locking pin; it is held in place by the ogive 9. The flange 58 holds the pin, but at the moment of discharge of the gun, the pin 56, due' to inertia, deforms the corresponding flange 58 and is forced to the bottom of the recess so that the bevelled end of the pin is forced onto the sharp inner corner of the groove 53 to lock the seating 8' on the base 8 of the head.

0n the periphery of the seating 8 is marked, opposite the indicating arrow 60, a scale 51, the divisions of which indicate seconds and fractions of a second. They may. however, also indicate a unit of length, for example, metres, decametres, hectometres, etc.

The balance wheel I6 is disposed in a recess in the seating 8 and has at the ends of each of its arms a notch 6|, in which is engaged a. ball 62 located at the entrance to a lateral passage 63 in the recess serving as a seating for the balance wheel. These passages are diametrically opposed to one another in relation to the centre of rotation of the balance wheel and extend apart in a slight curve from the field of gyration of the balance wheel. Before the shot is fired the balance wheelis locked by two locking pins 64 disposed on opposite sides of the balance wheel and the operation of which is the same asthat of the locking pin 50, i. e. these pins 64 are forced by inertia on firing, into their corresponding recess in the seating 8, under the action of the axial acceleration of the projectile, so that the balance wheel is released. Immediately the balls 62 are brought under the action of centrifugal force to the end of their passage 63 imparting an impulse to the balance wheel.

In the base 8 of the head is mounted a locking rod 65 having a screw threaded head 66 engaging in a screw-threaded hole in the base 8. This pin, when screwed to the bottom, isbrought either between the wings 25 of the driving wheel 23 or against one of the balls 39 in order to lock the driving device of the timing mechanism.

The fuse described has a dual purpose, that is to say, the projectile may be used as a contact shell, for a timed shell or for both combined. The operation is as follows:-

For use of the projectile as a contact projectile, the driving wheel 23 islocked by the rod 65, while the cap 29 is released by means of the rod 36. The balls 39 are located at the commencement of, i. e. at-the bottom of, the helicoidal track 38, while the zero mark of the scale 51 coincides with the arrow the percussion systems 28, 30 or 42, 43 are locked as described above so that the projectile may be transported and handled with safety. On firing, the percussion system 28, 30 is released by the fact that the safety spring encloses by inertia the pin 29 and the balls 3! are released from their seats and pass into the, passage 32 under the action of centrifugal force, as soon as the projectile receives a tangential acceleration. When the projectile strikes the obstacle, the cap 29 is forced forward by inertia so that the striker 28 acts on the percussion charge 36 and produces the explosion of the charge of the projectile.

For timed firing where the projectile is to explode at a definite moment, explosion of the projectile is caused by the percussion system Q2, 63 controlled by the timing mechanism. In this event, the percussion system 28, 30 may or may not be locked; if the latter is not locked, the projectile is double acting, i. e. acts as a time and a contact projectile. The interval of time elapsing between the discharge and the explosion of the projectile may be regulated precisely by means of the timing mechanism formed by a clockwork movement, the train of gearing of which and the frequency of vibrations of the balance wheel which are suited to thelarge initial velocities of modern artillery projectiles. For this purpose, the seating 8 may be turned with the ogive in relation to the base 8 of the head. The angular displacement of the seating 8' may be noted by means of the scale 51 and the arrow 6d. The driving wheel 23 of the clockwork movement being connected with the seating 8' by means of locking pins 50, it participates in the movement of rotation of the seating 8, as a result of which the blades or wings 25 carry with them the balls 39 over their helicoidal track 38 into a definite position in relation to the lateral opening 40. This reciprocal position of. the balls on the one hand and of the orifice, on the other, determines the path which the balls will have to traverse over their helicoidal track during the interval of time elapsing between the discharge and the bursting of the projectile. This path is, on the other hand, proportional to the length of the trajectory of the projectile up to the point of explosion of the latter. It is evident that only the ball nearest to the orifice M is adapted to operate on the striker 42, the other balls of the driving system being provided only for balancing purposes.

At the moment of. discharge, the pin 50 is lowered by inertia into its seat,.under the action of the axial acceleration of the projectile. The same applies to the three locking pins 56, which, by deforming their flange 58, are driven to the bottom of their recesses 55 and are forced on the corner of the groove -53 to lock the seating 8' on the base 8, of the head of the projectile.

When the projectile has left the mouth of the gun and the axial acceleration is terminated, the tangential acceleration of the projectile ensures that the locking pin or pins 5i, (since several may be provided), are thrown to the bot-- tom of their seatings 5!, as a result of which the driving wheel is released from the seating 8 forming the support for the clockwork movement. The same remark applies to the locking pin M which by inertia is thrown outwards against the action of the recoil spring 48, so that the striker M is released. Finally, the two balls 62, always under the action of centrifugal force, .roll towards the bottom of their respective passages 63, imparting an impulse to the balance wheel It which is set in oscillation under the action of the regulating spring I3. The oscillations of the balance wheel and, consequently, the operation of the clockwork movement, are then maintained by the driving action of the balls 39 on the blade wheel 23. The balls 39 subjected to the action of centrifugal force are displaced on their helicoidal track 38 of increasing radius and rotate the driving wheel 23 which, in turn, drives through the toothed crown 22 the time pinion H, the wheels the escapement and the balance wheel of the clockwork movement. When the most advanced ball 39 reaches the orifice 40, it is projected under the action of centrifugal force to the bottom of the recess M and strikes the striker 52, which ignites the percussion pellet 43 and, consequently, produces the explosion of the charge of the projectile. The orifice 40 could be closed by a flexible diaphragm to prevent the ball from prematurely entering the opening. The ball will pass through the inlet of the recess when it is subjected to centrifugal force.

It is to be understood that the driving device which has just been described is given solely by way of example and its construction maydifier from the form illustrated. Thus the device might have only one driving ball. The pitch or the inclination of the helicoidal track for the balls could be regular or irregular and more or less rapid. Finally, the track could be formed on the surface of a conical or substantially conical recess, but always on a helicoidal line of progressive radius.

I claim: I

l. A mechanical fuse for an artillery projectile comprising a timing mechanism and a striking mechanism controlled by said timing mechanism, including a helicoidal track within the projectile, a body movable along said track under the action of centrifugal force on discharge of the projectile,

said body being regulatable as to its initial position on said track, means for driving the timing mechanism, said driving means adapted to be driven by the movement of said body on said track, a passage leading from said track for the escape of said body from said track, a percussion fuse and a striker for operating said percussion fuse, said striker extending into said passage and adapted to be operated by said body escaping into said passage.

2. A mechanical fuse for an artillery projectile comprising a timing mechanism and a striking mechanism controlled by said timing mechanism including a helicoidal track within the projectile, said track having a progressive radius, a ball movable along said track under the action of centrifugal force on discharge of the projectile, said ball being regulatable as to its initial position on said track, means for driving the timing mechanism, said driving means adapted to be driven by the movement of said ball on said track, a passage leading from said track for the escape of said ball from said track, a percussion fuse and a striker for operating said percussion fuse, said striker extending into said passage and adapted to be operated by said ball.

3. A mechanical fuse for an artillery projectile comprising a timing mec'hanism and a striking mechanism controlled by said timing mechanism, said timing mechanism including a train of wheels, an escapement and a regulating means ed to be driven by the movement of said ball on said track, a passage leading from said track for the escape of said ball from said track, a percussion fuse and a striker for operating said percussion fuse, said striker extending into said passage and adapted to be operated by said ball.

4. A mechanical fuse for an artillery projectile comprising a timing mechanism and a striking mechanism controlled by said timing mechanism, a helicoidal track within the projectile, a plurality of balls movable along said track under the action of centrifugal force on discharge of the projectile, the initial position of said balls on said track being regulatable, means for driving the timing mechanism, said driving means including a rotatable member formed with channels engageable by said balls whereby said rotatable member is rotated by the movement of said balls in said track, a passage leading from said track for the escape of one of said balls from said track, a percussion fuse and a striker for operating said fuse, said striker having a portion extending into said passage and adapted to be operated by said ball in said passage.

5. A mechanical fuse for an artillery projectile comprising a timing mechanism and a striking mechanism controlled by said timing mechanism, said timing mechanism supported on the ogive of the projectile, said ogive normally rotatable on but adapted to be locked to the body of the projectile on discharge by locking means, said locking means including locking pins movable into locking position due to axial acceleration of the projectile, a helicoidal track within the projectile, a plurality of balls movable along said track under the action of centrifugal force produced on discharge of the projectile, the initial position of said balls on said track being regulatable, means for driving the timing mechanism, said driving means consisting of a spindle disposed axially of the projectile and a rotatable member mounted loosely on said spindle, said rotatable member formed with channels engageable by said balls and driven thereby, a passage leading from said track for the escape of one of said balls from said track, a percussion fuse and a striker for operating said fuse, said striker having a portion extending into said passage and adapted to be operated by said ball in said passage.

6. A mechanical fuse for an artillery projectile comprising a timing mechanism and a striking mechanism controlled by said timing mechanism, said mechanism including a helicoidal track within the projectile, a plurality of balls movable along said track under the action of centrifugal force produced on discharge of the projectile, means for driving the timing mechanism, said driving means consisting of a rotatable member formed with channels engageable by said balls and driven thereby, means for holding said rotatable member against rotation before discharge of the projectile, said means comprising locking pins releasable on discharge of the projectile by the axial and tangential acceleration imparted to the projectile by the propelling charge, a passage leading from said track for the escape of at leastone of said balls from said track, a percussion fuse and a striker for operating said fuse, said striker having a portion extending into said passage and adapted to be operated by said ball.

CARLO ARAGONE. 

